Botulism. 



99 



have lost the power to break through the trapdoor which leads to 

 the acetaldehyde stage in which they are capable of exercising 

 antiketogenetic effects. Apparently the only way the carbo- 

 hydrates affect ketogenesis is when they have come down to 

 the acetaldehyde stage. 



The modus operandi of the action of acetaldehyde on the ketone 

 bodies has already been discussed by Ringer and Frankel. They 

 suggested the possibility of acetaldehyde combining with /3-hy- 

 droxybutyric acid or acetoacetic acid giving rise to a substance 

 which is not ketogenetic. 



5i (1798) 



Botulism. 1 A method for determining the thermal death time of 

 the spores of Bacillus botulinus. 



By ERNEST C. DICKSON and GEORGINA S. BURKE. 



[From the Laboratory of Experimental Medicine, Stanford University 

 Medical School, San Francisco, Calif.] 



In the course of a series of experiments dealing with the 

 determination of the thermal death point of spores of Bacillus 

 botulinus in which the method of procedure recommended by 

 Bigelow and Estey 2 was followed with minor modifications, it was 

 found that in the daily transplanting of several hundred specimens 

 to the tubes in which the heated material was to be incubated, 

 it was inevitable that a certain small percentage of the tubes 

 became contaminated. The number of proved contaminations 

 was not large, less than 1 per cent, in a test of approximately 

 2,000 tubes, but because of the fact that one could not be abso- 

 lutely certain that any particular tube was free from contamina- 

 tion, it was impossible to draw accurate conclusions in any instance 

 where an unusual survival time was indicated. It was therefore 

 imperative that a method be devised in which the necessary 

 number of tubes per day could be handled with rapidity, and, at 



1 These experiments are a part of an investigation of Botulism which is being 

 made in California by the U. S. Public Health Service, Leland Stanford Junior 

 University and the University of California under a grant from the National Canners' 

 Association, the Canners' League of California and the California Olive Association. 



2 Bigelow and Estey, Jour. Infect. Dis., 1920, xxvii, 602. 



